Ask two players what sensitivity they use and you'll get answers that sound completely different — "I'm on 1.2," "I'm on 3.5" — yet their aim might feel almost the same. The confusion comes from comparing the wrong number. eDPI cuts through it by combining your two sensitivity settings into a single figure you can actually line up side by side.
eDPI stands for effective dots per inch, and the maths couldn't be simpler:
eDPI = mouse DPI × in-game sensitivity
Your DPI is a hardware setting on the mouse; your in-game sensitivity is a software multiplier applied on top of it. Neither one describes your aim on its own, because you can trade between them freely. Halve your DPI and double your sensitivity and nothing changes on screen. eDPI captures the thing that actually matters — the product of the two — in one number.
If you're not sure what your true DPI is (mice don't always deliver the number printed on the box), measure it first with the DPI Analyser, then do the multiplication.
Because DPI and sensitivity are interchangeable, two setups with the same eDPI move the crosshair by the same amount for the same hand movement — as long as you're in the same game. That's what makes eDPI so useful for comparison. When a pro shares their config and lists an eDPI of 800, you know their effective speed instantly, regardless of whether they got there via 400 DPI and 2.0 sensitivity or 800 DPI and 1.0.
Some worked examples make the interchangeability obvious:
All three feel identical inside the same title. (They aren't perfectly identical in every respect — a very high DPI can pick up more hand jitter, and a very low DPI can hit the sensor's resolution limits — but for the purpose of comparing speed, they're the same.)
Here's where people get burned. You find your perfect 800 eDPI in one game, set the same 800 eDPI in another, and it feels wrong — too fast, too slow, just off. The reason is yaw: every game rotates your view by a different amount per mouse count. CS2 uses 0.022 degrees per count at sensitivity 1; other games use entirely different constants. So the same eDPI turns you a different physical distance in each one.
eDPI is a within-game currency. It's like comparing prices in two countries by the raw number on the tag while ignoring the exchange rate — the figures line up, but they don't mean the same thing.
The number that is portable across games is cm/360 — the centimetres of physical mouse movement needed to spin a full 360 degrees. It's measured on your desk, not in the game's arbitrary units, so it describes your aim in real-world terms that survive any game's yaw.
To carry your muscle memory from one game to another, you match cm/360, not eDPI. A Sensitivity Converter does this for you: it takes your DPI and sensitivity in the source game, works out your cm/360, then finds the sensitivity in the target game that reproduces exactly that distance. The full reasoning is in How to Convert Mouse Sensitivity Between Games.
Rule of thumb: use eDPI to compare yourself to other players within a game; use cm/360 to move your own aim between games. They answer different questions.
eDPI norms cluster by game type, mostly because of how much precise aim versus fast movement each demands. As rough guides:
Treat these as orientation, not targets. Plenty of excellent players sit outside their genre's average because it fits their grip, arm-versus-wrist aiming style, and desk space.
Start by pinning down your real DPI, then calculate your current eDPI so you have a baseline. From there:
Getting comfortable with eDPI turns a vague, feelings-based debate into something you can measure and reason about. And once you understand why it stops working at the game boundary, you'll never make the mistake of copy-pasting a sensitivity number across two games again. For the wider picture on landing on a value that suits you, see How to Find Your Ideal Mouse Sensitivity.